Snatch-proof electric bulb and socket



May 31, 1960 E. BOLES ETAL SNATCH-PROOF ELECTRIC BULB AND SOCKET Filed June 3, 1959 2 Sheets-Sheet 1 F: 2...

INVENTOR5 514/4 0,455+

' flTTOKA/EZ May 31, 1960 BOLES EI'AL 2,939,104

SNATCH-FROOF ELECTRIC BULB AND SOCKET Filed June 3, 1959 2 Sheets-Sheet 2 INVENTOR. flu/4 B0455 BY 1- 055.575 6 501455 Zmoa SNATCH-lRQOF ELECTRIC BULB AND SOCKET Emil Boles, Mnhopac Ave., Box 28, Amawalk, N.Y., and Oreste G. Boles, 271 Beechwood Road, Oradell, NJ.

Filed June 3, 1959, Ser. No. 817,777

3 Claims. (Cl. 339-31) This invention relates to electric light bulbs and sockets therefor, and an object of the invention is the provision of a new and useful combination bulb and socket construction whereby when a bulb has once been screwed into the socket it cannot be removed without destroying the usefulness of the bulb.

In many electric light installations, especially where light bulbs are used out of doors, bulbs are frequently stolen, to the annoyance and at the loss of the owner. The present invention makes it disadvantageous to anyone who wishes to steal a bulb by simply unscrewing it from its socket, for such a person will discover that the bulb which he has stolen will be of no use to him.

Another object of the invention is the provision of a combination light bulb and socket therefor, wherein interlocking means is provided partly on the bulb and partly in the socket whereby the bulb after being screwed home cannot again be unscrewed without breaking the glass seal of the bulb and thus effectively ending its utility as a light bulb.

Nevertheless both the bulb and the socket of the present invention are so constructed that the former may be used in the usual manner with any standard socket and the latter may be used in the usual manner with any standard bulb, in cases where it is not desirable to have a theft-proof or snatch-proof installation.

The above broad as well as additional and more specific objects will be clarified in .the following description wherein reference numerals refer to like-numbered parts in the accompanying drawings. It is to be noted that the drawings are intended primarily for the purpose of illustration and that it is therefore neither desired nor intended to limit the invention necessarily to any or all of the exact details shown or described except insofar as they may be deemed essential to the invention.

Referring briefly to the drawings,

Fig. 1 is a central longitudinal sectional view through a combination electric light bulb and socket illustrating embodiments of the present invention, showing the bulb screwed part way but not all the way into the socket.

Fig. 2 is a view similar to Fig. l but showing the bulb screwed home in the socket.

Fig. 3 is a similar but exploded sectional view, showing the elements by which the standard bulb and socket are modified to attain the structure of the combination bulb and socket of the present invention, showing portions thereof at right angles to Fig. 1.

Fig. 4 is a sectional view taken on the line 4-4 of Fig. l.

Fig. 5 is a sectional view taken on the line 55 of Fig. 1.

Fig. 6 is a bottom plan view of the improved bulb as it may be taken on the line 6-6 of Fig. 3.

Fig. 7 is a fragmentary front view of the mutually interlocking portions and the adjacent parts, in the relative positions thereof shown in Fig. 1.

Fig. 8 is a sectional view taken on the line 8--8 of i nite States Patent 0 Fig. 3 but assuming that the light bulb is completely assembled.

Fig. 9 is a sectional view taken on the line 99 of Fig. 3.

Referring in detail to the drawings, the numeral 10 indicates a lamp socket of usual construction encased in the usual shell 11 which is separated from the threaded socket 12 by the usual insulating sleeve 13.

A diametrical metallic strip 14, which may be a disc, is secured to the porcelain or plastic body 15 of the socket by screws 16 passing through insulating sleeves 17. Between the heads of the screws and the sleeves 17 is positioned a fiat disc 18 of insulating material, and a metallic disc 19 which is toothed as described below, is cemented or otherwise secured to the insulating disc 18 and has the teeth 20 thereof extending downward. Holes 16a of larger diameter than the heads of the screws, are provided in the toothed metallic disc 19, in which the heads of the screws register out of contact with the metal disc 19. Aligned axial openings extend through the discs 18 and 19, as shown at 21 and 22, respectively, with the latter of larger diameter than the former. An axial contact element is provided on or in the strip 14, usually in the form of a spring finger 23 which may be cut out of the strip, to be engaged by the axial contact tip of the bulb in the vase of the usual socket; or this contact 23 may be in the form of a solid enlargement or boss, not shown, if desired.

Positioned below the toothed disc 19 is a second toothed disc 24 Whose teeth 25extend upward toward the teeth 20 of the disc 19. This disc has a punched out cylindrical upward axial projecting sleeve 26 which extends through the aligned openings 22 and 21 of the discs 19 and 18, respectively, and whose extremity Z7 is peened outward to provide a flange of larger diameter than the opening 21 and thus prevents complete separation of the two discs. A coiled spring 28 normally urges the two discs apart, i.e., it urges the disc 24 downward from-the fixed discs 18and 19. The teeth 20 of the disc 19 are inclined at an angle in a clockwise direction, Fig. 4, and the teeth 25 of the disc 24 are inclined in the opposite direction, Fig. 5, and the material of the discs out of which both sets of teeth are cut is thin and possesses resiliency.

The gas filled glass bulb per se, without the threaded male metallic shell 29, is shown at 30 and its sealed lower end iscemented or otherwise fixed in the shell 29. The seal for the bulb is provided in the form of an elongatedextension 31 integral with the glass bulb, and this extension is substantially rectangular in cross-section and projects beyond the glass base 32. The base of the shell 29 is closed by a shaped filling of porcelain or plastic.

In the case of the instant bulb, a metallic tube 34, rectangular or, as shown, elliptical in cross-section, has slots 36 cut out of the wall thereof along opposite ends of the long axis of the ellipse extending a distance along the tube, and the material cut out to form the slots is bent down to form opposed wings 35. The slotted end of this tube is inserted, from without, through a circular opening 40 through the base 33 before the wings 35 have been bent out of the slots 36. The opening 49 has a diameter equal to the largest cross-sectional dimension of the tube so that the tube is freely rotatable therein. If desired, that longitudinal portion of the tube which registers in the opening 40 may of course be made circular in cross-section, not shown.

After insertion of the tube 34 into the position shown in broken lines in Fig. 3, the wings 35 are bent outward and against the inside of the base 33, thus preventing expulsion of the tube from the base. Spaced from the tip end 39 of the tube, opposite the slotted end, a thin collar of resilient metal, shown at 38, is rigid with the tube and is positioned from the bases of the slots 36 a distance substantially equal to the, tbickness ofthe base 33at'its axis. Diametrically opposed resilient teeth 4 extend downward at an-acute angletfrom the collar 38 and face in a counter-clockwise direction. 'Cut into the outer surface of thebase 33 are diametrically opposed V-shaped notches 46 slanted as, shown in Fig; l to'permit only counter-clockwise rotation of the base 33, and hence of the bulb 30, with respect to the collar. .One lead 42 from thelamp filament41 is connected to the tube 34, and the other filament lead 43 is connected to the metallic shell 29;, both in the usual manner. With the bulb thus completely assembled as shown in Figs. 1 and 2, upon screwing it into thesOcket-IO and as it progresses thereinto, the tip 39- of the tube .34 will enter. the opening 44 through the disc 24, which opening forms the entrance into the cylindrical sleeve 26; the opening 44 is elliptical complementary to the tip 3 of the tube 34. After it has thus registered in the opening 44 continued screwing in of the bulb will cause the tip 39 to rotate the disc 24 with the bulb, as the collar 38 is thus rotated in synchronism with the bulb because of,the positive engagement of the teeth 45 in the. notches 46. When the disc 24 approaches sufiicientlyclose to the disc 19, the teeth 25 of the disc 24 will ride over the teeth 20, and ultimately the flange 27 of the sleeve 26 will engage the axial socket contact 23 to complete the circuit between the socket and the bulb filament.

If the attempt is made to unscrew the bulb, the positive engagement between the teeth 20 of the disc 19 and the teeth 25 of the disc 24 will prevent counter-clockwise rotation of the bulb. However, since the teeth 45 of the collar 38 freely permit counter-clockwise rotation of the bulb with respect to the tube 34, any force applied to the bulb to unscrew it'will cause the glass seal 31 to be twisted by the tube 34 so that the seal will be broken, since the seal will not tolerate anytwisting force. Once the seal has thus been broken the spoiled bulb may be readily removed and the disc 24 released from the disc 19. r

Wherever in the above the term elliptical has been used, it was used solely for the purpose of simplicity and by way of example, as the essential requirement regarding the parts to which the term was applied is that they be non-circular and complementary in outline.

A combination socket and bulb constructed as indi- I cated above is safe from any possibility of short circuiting. After a bulb has thus had its seal broken its inner surface becomes discolored so that its condition is readily recognized. 7

Thus a practical and useful combination of a socket and a snatch-proof bulb has been set forth. e i

The invention having thus been'described, what is claimed and desired to be secured by Letters Patent is as follows: 1

1. In a combination of an electric light socket having an internally threaded metallic Wall forming one electrode thereof and an axial metallic member forming the other electrode thereof and an electric light bulb having an insulated base sheathed in an externally threaded metallic shell and an axial electrode thereon and adapted to be screwed home into the socket in a clockwise direction, interengageable means'partly in the socket and partly on said base for locking the base against counterclockwise rotation thereof after the base has been screwed home into the socket, said interengaging means including two axially spaced discs insulated from the socket electrodes having interengageable ratchet teeth restricting ro tation of said base to said clockwise direction, that one of said discs adjacent said other of said electrodes being fixed in the socket and having a circular axial opening therethrough, the other of said discs having a non-circular axial opening therethrough, means normally urging said discs apart, said other disc having an axial cylindrical tube extending therefrom through said circular opening in said fixed disc and having means thereon limiting the distance of separation of the discs, said base having a complementary non-circular axial tubular projection registrable in said ope'ningin said other disc, the bulb includ- :ing an elongated 'glass axial seal of non-circular crosssection complementary to and registrablein said projection, and ratchet means partly on said projection and partly on said base restricting rotation of the base with respect to the projection to a counter-clockwise direction whence rotation of the base counterclockwise after the bulb is'screwed'home causes twisting and breaking of the seal.

2. In a combination of an electric light socket having an internally threaded metallic wall forming one electrode thereof and an axial metallic member forming the other electrode thereof and an electric light bnlb having an insulated base sheathed in an externally threaded metallic shell and an axial electrode thereon and adapted to be screwed home intothe socket in a clockwise direction, interengageable means partly in the socket and partly on said base for locking the base against counterclockwise rotation thereof after the base has been screwed home into the socket, said interengageable .means comprising a fixed disc mounted in and coaxial with the socket and insulated from said socket electrodes and having a circular axial opening therethrough, a second coaxial disc spaced outward from said fixed disc and having a cylindrical sleeve extending axially therefrom through said opening, the extremity of said sleeve having an external flange of larger diameter than said opening, resilient means normally urging said second disc outward from said fixed disc, ratchet teeth extending downward from said fixed disc toward said second disc inclined at an acute angle and facing in a clockwise direction, ratchet teeth extending from said second disc toward said fixed disc inclined at an acute angle and facing in a counterclockwise direction, said second disc having anon-circular opening therethrough into said sleeve, said base having a complementary non-circular axial projection registrable in said axial opening through said second disc, said flange being adapted to engage said other electrode of the socket when the bulb is screwed home.

3. In a combination as set forth in claim 2, said projection comprising a hollow tube, said bulb having an elongated glass seal coaxial with the base and non-circu-. lar in cross-section complementary to the inner crosssection of the tube, said tube being rotatably mounted in saidrbase, a collar rigid on the tube and positioned References Cited in the file of this patent UNITED STATES PATENTS 1,604,907 Goodridge ."Oct., 26, I926 

